﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace tinh_giai_thua
{
    class Program
    {
        static void Main(string[] args)
        {
            //TinhGiaiThua obj = new TinhGiaiThua();
            //int N = obj.Nhap();
            //int KQ = obj.giaithua(N);
            //Console.WriteLine(KQ);

            ToHop TH = new ToHop();
            int N = TH.NhapN();
            int K = TH.NhapK();
            long KQ = TH.TinhToHop(N, K);
            Console.WriteLine(KQ);
            
        }
    }
}
